Lazy Wave Riser Design in High Current and Mild Sour Environment

This paper presents an innovative design of Lazy Wave Steel Catenary Riser (LWSCR) associated with a major deepwater development in a new frontier and in very high current. The conventional LWSCR design with distributed buoyancy is not found acceptable considering fatigue design acceptance criteria in mild sour environment. The major design requirement is to meet acceptable design life of 20-yrs considering significant damage accumulated due to Vortex-induced-vibration (VIV) and motion fatigue. Further, other development basis including flow assurance requirements and reservoir souring are critical requirements for the design of the riser system. The paper presents a very useful insight in how several qualified technologies can be leveraged to result in a workable riser design in a very aggressive execution schedule. The results from the analyses of a production LWSCR are presented in the paper.